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digitalmars.D.learn - Trouble with Android and arsd.jni

reply burt <invalid_email_address cab.abc> writes:
Hello,

I'm trying to upgrade and improve an Android project I was 
working on a while ago. For this reason, I decided to upgrade my 
compiler to the newest LDC (v1.23.0).

I am using the arsd.jni library for the JNI headers and for 
initializing the runtime. However, I am getting linker errors, 
telling me that _tlsend, _tlsstart and __bss_end__ are missing.

So I tried to fix these by adding empty declarations for them 
myself (as I saw in another post):

```d
extern(C) __gshared
{
      section(".tdata")
     int _tlsstart = 0;
      section(".tcommon")
     int _tlsend = 0;
}
```

However, when doing this, it causes my app to crash, specifically 
on jni.d:1033 when calling `Runtime.initialize()`. The stack 
trace shows there is an assertion error in rt.sections_android in 
the foreach body of `getStaticTLSRange`.

I also tried adding an empty `void main() {}` instead, with the 
same result.


is emulated on Android or something. I have no clue what is going 
on and how to fix these errors, so if someone could help that 
would be much appreciated.

Thank you.
Sep 10 2020
parent reply kinke <noone nowhere.com> writes:
On Thursday, 10 September 2020 at 11:16:55 UTC, burt wrote:

 However, I am getting linker errors, telling me that _tlsend, 
 _tlsstart and __bss_end__ are missing.


Perhaps you happen to use some stale artifacts? These magic 
symbols aren't used anymore in druntime since LDC v1.21, and not 
defined by the compiler anymore. You also don't need the dummy 
main() anymore. The object file containing the undefined 
references should shed some light on what's still referencing 
them.
Sep 10 2020
parent reply burt <invalid_email_address cab.abc> writes:
On Thursday, 10 September 2020 at 11:58:51 UTC, kinke wrote:

 On Thursday, 10 September 2020 at 11:16:55 UTC, burt wrote:

 However, I am getting linker errors, telling me that _tlsend, 
 _tlsstart and __bss_end__ are missing.


 Perhaps you happen to use some stale artifacts? These magic 
 symbols aren't used anymore in druntime since LDC v1.21, and 
 not defined by the compiler anymore. You also don't need the 
 dummy main() anymore. The object file containing the undefined 
 references should shed some light on what's still referencing 
 them.


I'm not sure if this was the cause, but I believe I was using old 
libdruntime-ldc.a and libphobos2-ldc.a files which where 
downloaded from before v1.21. So that issue is fixed.

However, the app is still crashing when I load it, and there 
appears to be an issue in Runtime.initialize(), which is called 
from JNI_OnLoad(), which is defined in arsd.jni. The debugger 
tells me that it was calling `getStaticTLSRange`, which calls 
`safeAssert` in the `__foreachbody`, which fails and eventually 
aborts.
Sep 10 2020
parent kinke <noone nowhere.com> writes:
On Thursday, 10 September 2020 at 13:14:00 UTC, burt wrote:

 However, the app is still crashing when I load it, and there 
 appears to be an issue in Runtime.initialize(), which is called 
 from JNI_OnLoad(), which is defined in arsd.jni. The debugger 
 tells me that it was calling `getStaticTLSRange`, which calls 
 `safeAssert` in the `__foreachbody`, which fails and eventually 
 aborts.


That safeAssert would print a useful message, but I guess you can 
obtain the msg/reason via debugging as well. - This is most 
likely due to *not* using the required bfd linker (which is used 
by default when linking via LDC and otherwise selectable via 
`-linker=bfd`). If you're linking manually via clang, try 
`-fuse-ld=bfd`.
Sep 10 2020